From Center for Outcomes Research, The Children's Hospital of Philadelphia; Abramson Cancer Center, University of Pennsylvania; Perelman School of Medicine, University of Pennsylvania; The Wharton School, University of Pennsylvania; The Leonard Davis Institute of Health Economics, University of Pennsylvania; and The Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.

Acknowledgment: The authors thank Traci Frank, AA; Hong Zhou, MS; and Alexander Hill, BS (Center for Outcomes Research, The Children's Hospital of Philadelphia), for their assistance with this research.

Grant Support: By the Agency for Healthcare Research and Quality (grant R01 HS 018355) and the National Science Foundation (grant NSF SBS 1260782).